001 /* 002 $Id: LabelVerifier.java 3419 2006-01-19 00:07:02Z blackdrag $ 003 004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved. 005 006 Redistribution and use of this software and associated documentation 007 ("Software"), with or without modification, are permitted provided 008 that the following conditions are met: 009 010 1. Redistributions of source code must retain copyright 011 statements and notices. Redistributions must also contain a 012 copy of this document. 013 014 2. Redistributions in binary form must reproduce the 015 above copyright notice, this list of conditions and the 016 following disclaimer in the documentation and/or other 017 materials provided with the distribution. 018 019 3. The name "groovy" must not be used to endorse or promote 020 products derived from this Software without prior written 021 permission of The Codehaus. For written permission, 022 please contact info@codehaus.org. 023 024 4. Products derived from this Software may not be called "groovy" 025 nor may "groovy" appear in their names without prior written 026 permission of The Codehaus. "groovy" is a registered 027 trademark of The Codehaus. 028 029 5. Due credit should be given to The Codehaus - 030 http://groovy.codehaus.org/ 031 032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS 033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 043 OF THE POSSIBILITY OF SUCH DAMAGE. 044 045 */ 046 package org.codehaus.groovy.control; 047 048 import java.util.Iterator; 049 import java.util.LinkedList; 050 051 import org.codehaus.groovy.ast.ClassCodeVisitorSupport; 052 import org.codehaus.groovy.ast.stmt.BreakStatement; 053 import org.codehaus.groovy.ast.stmt.ContinueStatement; 054 import org.codehaus.groovy.ast.stmt.DoWhileStatement; 055 import org.codehaus.groovy.ast.stmt.ForStatement; 056 import org.codehaus.groovy.ast.stmt.Statement; 057 import org.codehaus.groovy.ast.stmt.SwitchStatement; 058 import org.codehaus.groovy.ast.stmt.WhileStatement; 059 060 /** 061 * This class checks the handling of labels in the AST 062 * 063 * @author Jochen Theodorou 064 */ 065 public class LabelVerifier extends ClassCodeVisitorSupport { 066 067 private SourceUnit source; 068 private LinkedList visitedLabels; 069 private LinkedList continueLabels; 070 private LinkedList breakLabels; 071 boolean inLoop=false; 072 boolean inSwitch=false; 073 074 public LabelVerifier(SourceUnit src) { 075 source = src; 076 } 077 078 protected SourceUnit getSourceUnit() { 079 return source; 080 } 081 082 private void init(){ 083 visitedLabels = new LinkedList(); 084 continueLabels = new LinkedList(); 085 breakLabels = new LinkedList(); 086 inLoop=false; 087 inSwitch=false; 088 } 089 090 protected void visitClassCodeContainer(Statement code) { 091 init(); 092 super.visitClassCodeContainer(code); 093 assertNoLabelsMissed(); 094 } 095 096 public void visitStatement(Statement statement) { 097 String label = statement.getStatementLabel(); 098 099 if (label!=null) { 100 for (Iterator iter = breakLabels.iterator(); iter.hasNext();) { 101 BreakStatement element = (BreakStatement) iter.next(); 102 if (element.getLabel().equals(label)) iter.remove(); 103 } 104 105 for (Iterator iter = continueLabels.iterator(); iter.hasNext();) { 106 ContinueStatement element = (ContinueStatement) iter.next(); 107 if (element.getLabel().equals(label)) iter.remove(); 108 } 109 110 visitedLabels.add(label); 111 } 112 113 super.visitStatement(statement); 114 } 115 116 public void visitForLoop(ForStatement forLoop) { 117 boolean oldInLoop = inLoop; 118 inLoop = true; 119 super.visitForLoop(forLoop); 120 inLoop = oldInLoop; 121 } 122 123 public void visitDoWhileLoop(DoWhileStatement loop) { 124 boolean oldInLoop = inLoop; 125 inLoop = true; 126 super.visitDoWhileLoop(loop); 127 inLoop = oldInLoop; 128 } 129 130 public void visitWhileLoop(WhileStatement loop) { 131 boolean oldInLoop = inLoop; 132 inLoop = true; 133 super.visitWhileLoop(loop); 134 inLoop = oldInLoop; 135 } 136 137 public void visitBreakStatement(BreakStatement statement) { 138 String label = statement.getLabel(); 139 boolean hasNamedLabel = label!=null; 140 if (!hasNamedLabel && !inLoop && !inSwitch) { 141 addError("the break statement is only allowed inside loops or switches",statement); 142 } else if (hasNamedLabel && !inLoop) { 143 addError("the break statement with named label is only allowed inside loops",statement); 144 } 145 if (label!=null) { 146 boolean found=false; 147 for (Iterator iter = visitedLabels.iterator(); iter.hasNext();) { 148 String element = (String) iter.next(); 149 if (element.equals(label)) { 150 found = true; 151 break; 152 } 153 } 154 if (!found) breakLabels.add(statement); 155 } 156 157 super.visitBreakStatement(statement); 158 } 159 160 public void visitContinueStatement(ContinueStatement statement) { 161 String label = statement.getLabel(); 162 boolean hasNamedLabel = label!=null; 163 if (!hasNamedLabel && !inLoop) { 164 addError("the continue statement is only allowed inside loops",statement); 165 } 166 if (label!=null) { 167 boolean found=false; 168 for (Iterator iter = visitedLabels.iterator(); iter.hasNext();) { 169 String element = (String) iter.next(); 170 if (element.equals(label)) { 171 found = true; 172 break; 173 } 174 } 175 if (!found) continueLabels.add(statement); 176 } 177 178 super.visitContinueStatement(statement); 179 } 180 181 protected void assertNoLabelsMissed() { 182 //TODO: report multiple missing labels of the same name only once 183 for (Iterator iter = continueLabels.iterator(); iter.hasNext();) { 184 ContinueStatement element = (ContinueStatement) iter.next(); 185 addError("continue to missing label",element); 186 } 187 for (Iterator iter = breakLabels.iterator(); iter.hasNext();) { 188 BreakStatement element = (BreakStatement) iter.next(); 189 addError("break to missing label",element); 190 } 191 } 192 193 public void visitSwitch(SwitchStatement statement) { 194 inSwitch=true; 195 super.visitSwitch(statement); 196 } 197 198 }